4.1

CVE-2026-5507: Session Cache Restore — Arbitrary Free via Deserialized Pointer

Analyzed
AliasesUBUNTU-CVE-2026-5507DEBIAN-CVE-2026-5507ALPINE-CVE-2026-5507
Published 09-04-2026Last modified 14-04-2026

Vulnerability summary

CVE-2026-5507 is a medium (CVSS 4.1) Deserialization of Untrusted Data vulnerability in wolfssl. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 6.6% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 4.1, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
4.1/10
010
Medium · v4.0 (CVE.org)
EPSS score
0.17%
0%100%
Low · -0.07 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 09-04-2026
    PublishedVulnerability first disclosed.
  2. 14-04-2026
    Last modifiedVulnerability information updated.

Description

When restoring a session from cache, a pointer from the serialized session data is used in a free operation without validation. An attacker who can poison the session cache could trigger an arbitrary free. Exploitation requires the ability to inject a crafted session into the cache and for the application to call specific session restore APIs.

CVSS metrics

7 scores · 5 sources · 2 versions

EPSS trend

Probability

0.17%

Chance of exploitation in the next 30 days

Percentile

7%

Versus all other CVEs

30-day change

Decrease -0.07 pp

From 0.24% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, administrative account, user interaction (CVSS vector). Other conditions: not stated in public data.

Alpine1 product
  • wolfssl< 5.9.1-r0
Debian1 product
  • wolfsslAll versions (No fix recorded)
Ubuntu1 product
  • wolfsslAll versions (No fix recorded)
Wolfssl1 product

4 vendors · 4 products

References

5 links